Glioblastoma multiforme (GBM) is the most malignant form of all primary adult brain tumors (See Reference 1). Although significant technical advances in surgical and radiation treatment for brain tumors have emerged, their impact on clinical outcome for patients has been disappointing (See References 2-4). Of the features that characterize GBM, none is more clinically significant than the capacity of glioma cells to infiltrate into normal brain tissue (See Reference 5). These invasive cells render tumor resection ineffective, and confer resistance to chemo- and radiation-therapy. Tests that identify invasive glioblastoma are necessary for purposes such as prediction of disease outcome and prediction of treatment effectiveness.